Zn batteries emerge as a promising class of energy storage devices with high energy density, low cost and high safety. Nonaqueous Zn electrolytes offer high interfacial stability yet suffer from sluggish interfacial charge transfer kinetics. Here, we report an eccentric Zn2+ solvation structure enabled by metal-organic polyhedrons (MOPs) in nonaqueous colloidal electrolytes, which facilitates charge transfer at electrode-electrolyte interface. The resultant Zn2+(ZrT)(DMF)(1) solvation structure features a large solvation sheath and a small ion-to-electrode distance, thus reducing the energy required for reorganizing the solvation sheath to accept electron. As a result, the MOPs-modulated colloidal electrolyte enables Zn anode with supreme stability for over 1200 h at 8 mA cm(-2) and 270 h at 12 mA cm(-2), along with high coulombic efficiency (similar to 99.8 % over 1000 cycles), notably exceeding the performance of conventional aqueous and nonaqueous electrolytes. The design principle of solvation sheath might be broadly applicable to other high-valence metal cation batteries.

Rechargeable magnesium batteries (RMBs) have emerged as a highly promising post-lithium battery systems owing to their high safety, the abundant Magnesium (Mg) resources, and superior energy density. Nevertheless, the sluggish kinetics has severely limited the performance of RMBs. Here, we propose an in-situ electrochemical activation strategy for improving the Mg-ion storage kinetics. We reveal that the activation strategy can effectively optimize surface composition of cathode that favors Mg-ion transport. Cooperating with lattice modifications, the CuSe | |Mg batteries exhibit a specific capacity around 160 mAh/g after 400 cycles with a capacity retention of over 91% at the specific current of 400 mA/g. Of significant note is the slight decay in specific capacity from 205 to 141 mAh/g has been observed with an increase in specific current from 20 to 1000 mA/g. This strategy provides insights into accelerating Mg-ion storage kinetics, achieving a promising performance of RMBs especially at high specific current. Rechargeable magnesium batteries offer safety, abundance, and high energy density but are limited by sluggish kinetics. Here, the authors proposed an in-situ electrochemical activation strategy to improve the interface composition and expand the lattice spacing of the (100) planes of CuSe, enhancing the kinetics of the rechargeable magnesium batteries.

Proton batteries are promising candidates for next-generation large-scale energy storage in extreme conditions due to the small ionic radius and efficient transport of protons. Hydrogen gas, with its low working potentials, fast kinetics, and stability, further enhances the performance of proton batteries but necessitates the development of novel electrolytes with low freezing points and reduced corrosion. This work introduces a localized water restriction strategy by incorporating a tertiary component with a high donor number, which forms strong bonds with water molecules. This approach restricts free water molecules and reduces the average hydrogen bond ratio and strength. As-prepared ternary eutectic electrolytes lowered the freezing point to −103 °C, significantly lower than the traditional binary electrolyte (9.5 m H 3 PO 4 , −93 °C). This electrolyte is highly compatible with the Cu 0.79 Co 0.21 [Fe(CN) 6 ] 0.64  ⋅ 4H 2 O (CoCuHCF) cathode, reducing material dissolution and current collector corrosion. The H 2 ||CoCuHCF battery using this electrolyte demonstrated a high-power density of 23664.3 W kg −1 , excellent performance at −80 °C, and stable cyclability over 1000 cycles (>30 days) at −50 °C. These findings provide a framework for proton electrolytes, highlighting the potential of hydrogen batteries in challenging environments.

Near-neutral zinc-air batteries (ZABs) have garnered significant research interest due to their high energy density, exceptional electrochemical reversibility, and adaptability to ambient air. However, these batteries suffer from substantial electrochemical polarization, low energy efficiency, and poor rate performance. In this study, a mesoporous carbon (meso-C) with a high specific surface area (1081 m2 g-1 ) and abundant porous structure for the cathode of near-neutral ZABs using a scalable synthesis method is prepared. The meso-C-based cathode is endowed with stable hydrophobicity and abundant electrochemical active sites, which considerably improve the energy efficiency, rate performance, and cycle life of the battery compare to commercial carbon black-based cathode when applied to near-neutral ZABs with 1 mol kg-1 (1 m) zinc acetate and 1 m zinc trifluoromethanesulfonate electrolytes. Additionally, the mesopores of meso-C facilitate the construction of better three-phase reaction interfaces and contribute to better electrochemical reversibility. The work presents a general and scalable approach for carbon materials in the cathode of near-neutral ZABs.

Two-electron oxygen reduction reaction (2e- ORR) is of great significance to H2O2 production and reversible nonalkaline Zn-air batteries (ZABs). Multiple oxygen-containing sp2-bonded nanocarbons have been developed as electrocatalysts for 2e- ORR, but they still suffer from poor activity and stability due to the limited and mixed active sites at the edges as well as hydrophilic character. Herein, graphdiyne (GDY) with rich sp-C bonds is studied for enhanced 2e- ORR. First, computational studies show that GDY has a favorable formation energy for producing five-membered epoxy ring-dominated groups, which is selective toward the 2e- ORR pathway. Then based on the difference in chemical activity of sp-C bonds in GDY and sp2-C bonds in CNTs, we experimentally achieved conductive and hydrophobic carbon nanotubes (CNTs) covering O-modified GDY (CNTs/GDY-O) through a mild oxidation treatment combined with an in situ CNTs growth approach. Consequently, the CNTs/GDY-O exhibits an average Faraday efficiency of 91.8% toward H2O2 production and record stability over 330 h in neutral media. As a cathode electrocatalyst, it greatly extends the lifetime of 2e- nonalkaline ZABs at both room and subzero temperatures.

Rechargeable zinc–air batteries (ZABs) are considered to be one of the most sustainable alternative systems in a post-lithium-ion future owing to their lowest possible dependency on critical raw materials and high theoretical energy densities. However, their performance is still not up to par with their potential because of the sluggish kinetics of the oxygen reduction reaction. Here we report a single-atom catalyst design that transforms the sluggish four-electron oxygen reduction reaction into a fast two-electron pathway and enables a zinc peroxide (ZnO 2 ) chemistry in ZABs. With accessible FeN 2 S 2 active sites on mesoporous graphene, the catalyst serves to promote transport of electrolyte, oxygen and electron and confines the growth of ZnO 2 , which would otherwise form dead products. As a result, as-fabricated ZAB in a neutral electrolyte shows a voltage as high as 1.2 V at 0.2 mA cm −2 , a high round-trip efficiency of 61% and an excellent operation stability beyond ∼400 h. This work provides guidelines for the rational design of multifunctional cathodes and would accelerate the adoption of sustainable batteries in the metal–air category.

Along with the booming research on zinc metal batteries (ZMBs) in recent years, operational issues originated from inferior interfacial reversibility have become inevitable. Presently, single-component electrolytes represented by aqueous solution, "water-in-salt," solid, eutectic, ionic liquids, hydrogel, or organic solvent system are hard to undertake independently the task of guiding the practical application of ZMBs due to their specific limitations. The hybrid electrolytes modulate microscopic interaction mode between Zn2+ and other ions/molecules, integrating vantage of respective electrolyte systems. They even demonstrate original Zn2+ mobility pattern or interfacial chemistries mechanism distinct from single-component electrolytes, providing considerable opportunities for solving electromigration and interfacial problems in ZMBs. Therefore, it is urgent to comprehensively summarize the zinc chemistries principles, characteristics, and applications of various hybrid electrolytes employed in ZMBs. This review begins with elucidating the chemical bonding mode of Zn2+ and interfacial physicochemical theory, and then systematically elaborates the microscopic solvent structure, Zn2+ migration forms, physicochemical properties, and the zinc chemistries mechanisms at the anode/cathode interfaces in each type of hybrid electrolytes. Among of which, the scotoma and amelioration strategies for the current hybrid electrolytes are actively exposited, expecting to provide referenceable insights for further progress of future high-quality ZMBs.

Deep eutectic electrolytes (DEE) have emerged as an innovative approach to address the instability and safety issues of lithium metal batteries at elevated temperatures. However, in practice, there is often an undesirable incompatibility between the eutectic mixture and electrodes, and also an insufficient reduction stability of DEE due to the increased Li + concentration. Herein, we designed a new DEE by utilizing weakly solvating tetrahydropyran (THP) solvent. Due to the high reduction resistance of THP and concentrated lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), this DEE demonstrates enhanced compatibility with Li metal anode and high temperature tolerance with LiMn 2 O 4 cathode. The Li||LiMn 2 O 4 cell (1.6 mAh cm −2 ) shows a high capacity retention of 96.02 % after 600 cycles at room temperature. More importantly, this Li||LiMn 2 O 4 cell achieves a remarkable high-temperature performance with a high capacity retention of 91.72 % after 120 cycles and low self-discharge after storage for 240 hours at a high temperature of 55 °C, which is critical for LiMn 2 O 4 cathode. Overall, this electrolyte design provides an alternative pathway for the development of DEEs for high-temperature and high-voltage lithium metal batteries, which can also be expanded to other batteries.

Near -neutral zinc -air batteries show great promise for long -cycle applications in ambient air owing to their impressive deposition/stripping compatibility with zinc anodes and greater chemical stability towards CO2 in ambient air compared to batteries with traditional alkaline electrolytes. However, the inherent water volatilization of liquid electrolytes and the flexibility of electrolytes required for wearable devices severely limit the practical application of this system. In this study, a fumed SiO2- based composite hydrogel polymer electrolyte (SiO2-HPE) was prepared for application in near -neutral zinc -air batteries. The design of the SiO2-HPE was carried out considering the following three aspects. Firstly, it is widely acknowledged that the polyacrylamide polymer skeleton is beneficial to excellent ionic conductivity and the mechanical strength of the SiO2-HPE. Secondly, fumed SiO2 bearing multiple silicon hydroxyl groups is a suitable option as a water -retaining additive. Thirdly, the near -neutral liquid electrolyte (1 mol center dot kg-1 Zn(OTf)2) absorbed in the SiO2-HPE is stable towards CO2 in ambient air. In conclusion, these three aspects of the electrolyte design contribute to the practical application of the SiO2-HPE. Raman spectroscopy and scanning electron microscopy revealed that the synthesized SiO2-HPE exhibited a high degree of polymerization, plentiful surface pores, and a uniform distribution of elements. According to the infrared and Raman spectra, the abundant hydroxyl groups located on the surface of the SiO2 particles enhanced water molecule binding by altering the hydrogen bond network within the SiO2-HPE. This conclusion was further confirmed by thermogravimetry and differential scanning calorimetry. After exposure to ambient air (30% relative humidity) for 96 h, the SiO2-HPE exhibited a water retention capacity of 49.52%, which is 6.23% and 1.73% higher than those for 1 mol center dot kg-1 Zn(OTf)2 and the HPE (hydrogel polymer electrolyte without SiO2). Moreover, owing to the dynamic recombination of the hydrogen bonds between the silicon hydroxyl groups and the gel skeleton, SiO2-HPE exhibited a higher mechanical strength and modulus than HPE under tensile and compressive conditions, respectively. This further rendered it an ideal electrolyte for flexible zinc -air batteries. The near -neutral zinc -air battery assembled with the SiO2-HPE exhibited a cycle life of up to 200 h under 30% relative humidity, far exceeding those of 1 mol center dot kg-1 Zn(OTf)2 and the HPE. Based on such remarkable performance, the flexible near -neutral zinc -air battery device assembled by the SiO2-HPE has shown a satisfactory performance under special conditions, such as bending and cutting, and can be used as a power supply for different electronic devices, making it a promising next -generation electrochemical energy storage device. Overall, this work provides new insight into the development of flexible zinc -air battery devices with long-term stability in ambient air.

Single-crystal lithium-nickel-manganese-cobalt-oxide (SC-NMC) is attracting increasing attention due to its excellent structural stability. However, its practical production faces challenges associated with complex precursor preparation processes and severe lithium-nickel cation mixing at high temperatures, which restricts its widespread application. Here, a molten-salt-assisted method is proposed using low-melting-point carbonates. This method obviates the necessity for precursor processes and simplified the synthetic procedure for SC-NMC down to a single isothermal sintering step. Multiple characterizations indicate that the acquired SC-LiNi0.6Mn0.2Co0.2O2 (SC-622) exhibits favorable structural capability against intra-granular fracture and suppressive Li+/Ni2+ cation mixing. Consequently, the SC-622 exhibits superior electrochemical performance with a high initial specific capacity (174 mAh g(-1) at 0.1 C, 3.0-4.3 V) and excellent capacity retention (87.5% after 300 cycles at 1C). Moreover, this molten-salt-assisted method exhibits its effectiveness in directly regenerating SC-622 from spent NMC materials. The recovered material delivered a capacity of 125.4 mAh g(-1) and retained 99.4% of the initial capacity after 250 cycles at 1 C. This work highlights the importance of understanding the process-structure-property relationships and can broadly guide the synthesis of other SC Ni-rich cathode materials.

The practical applications of zinc metal anode are restricted by detrimental dendrite growth and hydrogen evolution reaction (HER), especially at high current densities. Previous works have demonstrated that constructing Zn(002) texture could effectively suppress dendrite growth and HER. However, the surface grain distribution of commercial zinc metal remains indistinct. Herein, a simple mechanical grinding approach is demonstrated to construct (002)-textured zinc metal anodes. After grinding, the (002) relative texture coefficient of commercial zinc metal increases from 10.58 to 42.28, indicating a significant more (002) planes exposure. As prepared (002)-textured zinc anode exhibits a high critical current density of 141 mA cm-2 and stably cycles for over 1500 cycles at 50 mA cm-2 and 1 mAh cm-2. Benefiting from the stability and fast kinetics of this (002)-textured zinc anode, the zinc-ion capacitor achieves a power density of 8500 W kg-1 and long cycle over 10 000 cycles with Coulombic efficiency (CE) exceeding 99.9%. This work provides both fundamental and practical insights for dendrite-free and HER-suppressed zinc metal anodes and inspiring guidance for other metal batteries. Zn(002) texture effectively suppresses dendrite growth and hydrogen evolution reaction. Leveraging lowest binding energy, mechanical grinding selectively disrupts the (002) crystal plane. (002) Relative texture coefficient increases to 42.28. Therefore, (002)-textured zinc anode exhibits a high critical current density of 141 mA cm-2 and zinc-ion capacitor achieves a power density of 8500 W kg-1 and long cycle over 10 000 cycles. image

Rechargeable aqueous zinc batteries are promising energy storage devices because of their low cost, high safety, and high energy density. However, their performance is plagued by the unsatisfied cyclability due to the dendrite growth and hydrogen evolution reaction (HER) at the Zn anode. Herein, it is demonstrated that the concentrated hybrid aqueous/non‐aqueous ZnCl 2 electrolytes constitute a peculiar chemical environment for not only the Zn‐ions but also water molecules. The high concentration of chloride ions substitutes the H 2 O molecular in the solvation structure of Zn 2+ , while the acetonitrile further interacts with H 2 O to decrease its activity. The hybrid electrolytes both inhibit the dendrite formation and HER, enabling an ultrahigh average Coulombic efficiency of 99.9% in the Zn||Cu half‐cell and a highly reversible Zn plating/stripping with a low overpotential of 21 mV. Using this hybrid electrolyte, the Zn||polytriphenylamine (PTPAn) full cell deliveres a high discharge capacity of 110 mAh g −1 , a high power density of 9200 W kg −1 at 100 °C and maintains 85% of the capacity for over 6000 cycles at 10 °C. This study provides a deep understanding between the solvation structure and columbic efficiency of Zn anode, thus inspiring the development for stable Zn batteries.

Abstract In situ formation of a stable interphase layer on zinc surface is an effective solution to suppress dendrite growth. However, the fast transport of bivalent Zn-ions within the solid interlayer remains very challenging. Herein, we engineer the SEI components and enable superior kinetics of Zn metal batteries under harsh conditions through regulating the sequence of interfacial chemical reaction. With the differences in chemical reactivity of trimethyl phosphate co-solvent and trifluoromethanesulfonate anions in the Zn2+-solvation shell, Zn3(PO4)2 and ZnF2 are successively generated on Zn metal surface to form a gradient ZnF2–Zn3(PO4)2 interphase. Mechanistic studies reveal the outer ZnF2 facilitates Zn2+ desolvation and inner Zn3(PO4)2 serves as channels for fast Zn2+ transport, contributing to long-term cycling at subzero temperatures. Impressively, the gradient SEI enables a high lifespan over 7000 hours in Zn symmetric cell and a capacity retention of 86.1% after 12000 cycles in Zn–KVOH full cell at –50 °C.

Non-alkaline zinc-air batteries (ZABs) that use reversible O-2/ZnO2 chemistry exhibit excellent stability and superior reversibility compared to conventional alkaline ZABs. Unlike alkaline ZABs, ZnO2 discharge products are generated on the surface of the air cathodes in non-alkaline ZABs, requiring more gas-liquid-solid three-phase reaction interfaces. However, the kinetics of reported ZABs based on carbon black (CB) is far from satisfactory due to the insufficient reaction areas. The rational structural design of the air cathode is an effective way to increase active surfaces to further enhance the performance of non-alkaline ZABs. In this study, multi-walled carbon nanotubes (MW-CNTs) with unique mesoporous structures and high pore volumes are selected to replace CB in the air cathode preparation. Due to the larger electrochemically active surface area, superior hydrophobicity, and uniform electroconductibility of MW-CNTs-based cathodes, primary ZABs exhibit high specific capacity (704 mAh gZn(-1)) with a Zn utilization ratio of 85.85% at 1.0 mA cm(-2), excellent discharge rate performance, and negligible self-discharge. Furthermore, rechargeable ZABs also demonstrate outstanding rate capability and excellent cycling stability at various current densities. This work provides a fundamental understanding of the criteria for the cathode design of non-alkaline ZABs, thus opening a new pathway for more sustainable ZABs.